Caption: Water flea. Coloured light micrograph (LM) of a water flea (Simocephalus vetulus), showing a batch of eggs developing in the dorsal surface of the carapace (top centre). This is a small freshwater crustacean commonly found in ponds. It swims by beating its branched antennae (left). It feeds on algae, which it wafts into its mouth by beating small limbs on its carapace. During the spring and summer, females reproduce using parthenogenesis (growth of egg without male fertilisation). Males appear in autumn and sexual reproduction follows. The resulting eggs overwinter in the female and are laid in early spring.